146514-21-8Relevant articles and documents
One-step stereospecific strategy for the construction of the core structure of the 5, 11-methanomorphanthridine alkaloids in racemic as well as in optically pure form: Synthesis of (±)-pancracine and (±)- brunsvigine
Pandey, Ganesh,Kumar, Ravindra,Banerjee, Prabal,Puranik, Vedavati G.
scheme or table, p. 4571 - 4587 (2011/10/03)
The unique core structure of the complex pentacyclic 5, 11-methanomorphanthridine has been constructed stereospecifically in one step by an intramolecular [3+2] cycloaddition of a non-stabilized azomethine ylide (AMY), generated by the sequential double desilylation of 14 using AgIF as a one-electron oxidant. The formation of the single diastereomer in the key step is explained by the preferred transition state produced by endo attack of the AMY on the "Re" face of the dipolarophile. An asymmetric version of the cycloaddition using a chiral dipolarophile was applied to construct the core structure 68 with 63% ee. This strategy was successfully applied to the formal synthesis of (±)-pancracine and the total synthesis of (±)-brunsvigine. An unprecedented and interesting skeletal rearrangement product 49 was observed during the attempted assembly of the E ring from 46 through Horner-Wadsworth-Emmons reactions. Mechanisms involving azetidinium salt formation or the Grob-type fragmentation are advanced to explain the observed rearrangement.
Convergent approach toward the synthesis of the stereoisomers of C-6 homologues of 1-deoxynojirimycin and their analogues: Evaluation as specific glycosidase inhibitors
Pandey, Ganesh,Dumbre, Shrinivas G.,Khan, M. Islam,Shabab
, p. 8481 - 8488 (2007/10/03)
A new and stereoselective strategy is developed to synthesize an appropriate template 9 to obtain C-6 homologues of 1-deoxyazasugars such as 1-deoxy-D-galactohomonojirimycin (S), 1-deoxy-4-hydroxy-methyl-D- glucohomonojirimycin (6), and their enantiomers. The template 9 is also used to obtain neutral nonbasic pseudo-glyconolactam (8), C-4 amino, and methyl analogues of 1-deoxy-homonojirimycin as new analogues of 1-deoxyhomoazasugars. Compound 5 is found to be a potent and specific inhibitor to α-galactosidase (Ki = 1.7 μM). Similarly compounds 6 (K i = 28 μM), ent-5 (Ki = 129 μM), and ent-6 (K i = 12 μM) exhibited specific inhibition of β-glucosidase.